U.S. patent application number 11/279060 was filed with the patent office on 2006-11-02 for method and apparatus for non-disruptive call modification.
This patent application is currently assigned to NORTEL NETWORKS LIMITED. Invention is credited to Jean-Pierre COUPAL, Stephen SHEW, Darek SKALECKI.
Application Number | 20060245413 11/279060 |
Document ID | / |
Family ID | 37307546 |
Filed Date | 2006-11-02 |
United States Patent
Application |
20060245413 |
Kind Code |
A1 |
SKALECKI; Darek ; et
al. |
November 2, 2006 |
METHOD AND APPARATUS FOR NON-DISRUPTIVE CALL MODIFICATION
Abstract
A method and system for changing the extent of data plane
resources controlled by a control plane for a network connection
which spans a contiguous set of nodes controlled by existing
network control resources is disclosed. This is done in a
non-disruptive manner. This typically involves two steps: i)
Creating a new set of control plane resources for said network
connection such that said data plane resources are shared with said
existing network control resources; and ii) then terminating the
existing network control resources such that said data plane
resources are fully transferred to the new set of control plane
resources without disrupting said network connection. The existing
network control resources can be either a control plane resource or
a non control plane resource. An example of a non control plane
resource is network management software (e.g., an OSS (Operation
Support System)), which forms part of the Management Plane. It
should be noted that this does not need to be done for a complete
end-to-end connection, but rather can be executed for the portion
of the end-to-end connection which is to be controlled by the
control plane.
Inventors: |
SKALECKI; Darek; (Kanata,
CA) ; SHEW; Stephen; (Kanata, CA) ; COUPAL;
Jean-Pierre; (Gatineau, CA) |
Correspondence
Address: |
BORDEN LADNER GERVAIS LLP
WORLD EXCHANGE PLAZA
100 QUEEN STREET SUITE 1100
OTTAWA
ON
K1P 1J9
CA
|
Assignee: |
NORTEL NETWORKS LIMITED
2351 Boulevard Alfred-Nobel
St. Laurent
CA
|
Family ID: |
37307546 |
Appl. No.: |
11/279060 |
Filed: |
April 7, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60675870 |
Apr 29, 2005 |
|
|
|
Current U.S.
Class: |
370/351 |
Current CPC
Class: |
H04M 3/2263 20130101;
H04L 65/1083 20130101; H04L 47/10 20130101; H04Q 3/0062 20130101;
H04L 29/06027 20130101; H04L 65/80 20130101; H04M 7/06 20130101;
H04L 67/14 20130101 |
Class at
Publication: |
370/351 |
International
Class: |
H04L 12/28 20060101
H04L012/28 |
Claims
1. A method for changing the extent of data plane resources
controlled by a control plane for a network connection which spans
a contiguous set of nodes, said network connection controlled by
existing network control resources, said method comprising the
steps of: i) Creating a new set of control plane resources for said
network connection such that said data plane resources are shared
with said existing network control resources; and ii) then
terminating the existing network control resources such that said
data plane resources are fully transferred to the new set of
control plane resources without disrupting said network
connection.
2. The method of claim 1, wherein at least some of said existing
network control resources comprise existing control plane
resources.
3. The method of claim 1, wherein the number of nodes controlled by
said new set of control plane resources differs from the number of
nodes controlled by said existing control plane resources.
4. The method of claim 2 which is carried out for a call which
includes said connections.
5. The method of claim 3 which is carried out for a call which
includes said connections.
6. A method as claimed in claim 1 wherein step i) comprises:
creating connection control states for the new set of control plane
resources on every node; and mapping the existing data plane
resources to each new connection control state.
7. A method as claimed in claim 1 wherein step i) comprises:
creating call control states for the new set of control plane
resources; creating connection control states for the new set of
control plane resources on every node; associating the new
connection control state with the new call states; and mapping the
existing data plane resources to each new connection control
state.
8. A method as claimed in claim 1 wherein the new set of control
plane resources include modified data plane resources.
9. A method as claimed in claim 1, wherein at least a first subset
of said existing network control resources are control plane
resources and at least a second subset of said existing network
control resources are non control plane resources, and wherein the
number of control plane resources in said new set of control plane
resources is larger than said first subset, thus lengthening the
set of data plane resources under control plane influence.
10. A method as claimed in claim 1, wherein at least a subset of
said existing network control resources are control plane
resources, and wherein the number of control plane resources in
said new set of control plane resources is smaller than said
subset, thus reducing the original set of data plane resources
under control plane influence.
11. A method as claimed in claim 10 further comprising transferring
data plane resources no longer controlled by control plane
resources to non control plane resources.
12. A method as claimed in claim 1, where in a single connection is
replaced by two or more connections spanning the resources of an
existing data plane connection, thus splitting the original
connection.
13. A method as claimed in claim 4, where in a single call is
replaced by two or more calls spanning the resources of an existing
data plane connection, thus splitting the original call.
14. A method as claimed in claim 1, wherein two connections that
independently span a continuous data plane connection are replaced
by a single connection that spans all of the original data plane
connection, thus merging the two original connections.
15. A method as claimed in claim 4, wherein two calls that
independently span a continuous data plane connection are replaced
by a single call that spans all of the original data plane
connection, thus merging the two original calls.
16. A method as claimed in claim 5, wherein two calls that
independently span a continuous data plane connection are replaced
by a single call that spans all of the original data plane
connection, thus merging the two original calls.
17. A method as claimed in claim 1, wherein a single connection is
modified so that the head and tail of the connection is
reversed.
18. A method as claimed in claim 4, wherein a single call is
modified so that the head and tail of the call is reversed.
19. A method as claimed in claim 5, wherein a single call is
modified so that the head and tail of the call is reversed.
20. A method as claimed in claim 1, wherein a switched connection
is modified to be a soft permanent connection.
21. A method as claimed in claim 1, wherein a soft permanent
connection is modified to be a switched connection.
22. A method as claimed in claim 1, wherein a call containing
multiple call controllers is replaced by a call with a different
number of call controllers.
23. A method as claimed in claim 7, wherein a call containing
Exterior Network-Network Interface is replaced by a call that does
not contain that Exterior Network-Network Interface.
24. A method as claimed in claim 7, wherein a call is replaced by a
call that includes an additional Exterior Network-Network
Interface.
25. A method of controlling a network connection between X nodes in
a network, wherein a first subset Y of said nodes is controlled by
a control plane, and a second subset (X-Y) is not controlled by a
control plane, comprising adjusting Y by a delta Z without
adjusting the data plane connections between said X nodes.
26. A method as claimed in claim 25 wherein said adjusting Y step
comprises: a. establishing new control plane connections for Y+Z in
parallel to the existing control plane connections for Y, said new
control plane connections and said existing control plane
connections sharing the same data plane resources; and b. then
terminating the existing control plane connections such that said
data plane resources are fully transferred to the new control plane
connections without disrupting said network connection.
27. A method for changing the extent of data plane resources
controlled by a call or connection comprising the steps of:
Creating a new call/connection or multiple calls/connections such
that data plane resources are shared with existing
call(s)/connection(s) and optionally non-control plane connection
management state. Terminating the existing call(s)/connection(s)
and optionally the non-control plane management state, such that
data plane resources are fully transferred to the new
call/connection or multiple calls/connections in the control
plane.
28. A network for implementing the method of claim 25.
29. A Network node for a network as claimed in claim 28.
30. A computer program product embodied in a machine-readable
medium tangibly embodying computer executable instructions for
updating a network node to be compliant with any of the above
claims.
31. A computer program product embodied in a machine-readable
medium tangibly embodying computer executable instructions for
controlling at least a portion of a network of X nodes, wherein at
least a subset Y of said nodes is controlled by a first control
plane connection, said computer executable instructions comprising
computer executable instructions for establishing a second control
plane connection between a second subset Z of said nodes in such a
manner that said second control plane connection shares data plane
resources with said first control plane.
32. The computer executable instructions as claimed in claim 29
wherein said computer executable instructions for establishing a
second control plane connection comprises: a. computer executable
instructions for establishing a second control plane connection in
parallel with said first control plane, such that both said first
and second control plane connections share at least some data plane
resources; and b. computer executable instructions for terminating
the existing first control plane connection such that said shared
data plane resources are fully transferred to the said second
control plane connection without disrupting said data plane
resources.
33. The computer executable instructions as claimed in claim 30
wherein Z does not equal Y.
34. The computer executable instructions as claimed in claim 30
wherein Z=Y, but the data plane resources of Z differ from the data
plane resources of Y.
35. The computer executable instructions as claimed in claim 30
wherein said computer executable instructions a second control
plane connection further comprise instructions for: a. creating new
connection control states for the second control plane connection
on each of said Z nodes; and b. mapping said shared data plane
resources to each new connection control state.
36. The computer executable instructions as claimed in claim 30
wherein said computer executable instructions a second control
plane connection further comprise instructions for: a. creating new
call control states for the second control plane connection; b.
creating new connection control states for the second control plane
connection on each of said Z nodes; c. associating the new
connection control states with the new call states; and mapping
said shared data plane resources to each new connection control
state.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority of U.S.
Provisional Patent Application No. 60/675,870 filed Apr. 29, 2005,
which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to telecommunication
networks. More particularly, the present invention relates to such
networks which utilize a control plane to control calls.
BACKGROUND OF THE INVENTION
[0003] Today's telecommunication networks are increasingly
characterized by the separation of the control and data planes.
That is, data plane connections used to transport traffic and their
associated control plane connections used to manage the data plane
connections are somewhat independent.
[0004] All network operators over time increase or decrease the
sizes of their networks, or alter the configuration their networks.
There are many business reasons for this, including mergers,
divestitures or re-organizations of carriers and enterprises, or
the addition of updated equipment. Network operators may want to
make a variety of adjustments to their networks, including growing
(e.g., adding nodes) and/or shrinking (e.g., removing nodes). Some
of adjustments do not necessarily affect the data plane which
actually carries the user traffic. However, these adjustments do
affect the control plane and/or network management systems.
Examples of such adjustments include splitting, merging and/or
modifying the span of control of existing connections. In other
words, modifying the span of control plane connections. These
adjustments will be discussed in more detail below.
[0005] However there are some connections which have long
durations, and it is highly desirable to avoid any disruption to
services offered through these connections while making said
adjustments.
[0006] It is, therefore, desirable to provide a method for
adjusting the span of control of a network in a non-disruptive
manner.
SUMMARY OF THE INVENTION
[0007] Generally, the present invention provides a method and
system for changing the extent of data plane resources controlled
by a control plane for a network connection which spans a
contiguous set of nodes controlled by existing network control
resources. This is done in a non-disruptive manner. This typically
involves two steps:
[0008] i) Creating a new set of control plane resources for said
network connection such that said data plane resources are shared
with said existing network control resources; and
[0009] ii) then terminating the existing network control resources
such that said data plane resources are fully transferred to the
new set of control plane resources without disrupting said network
connection.
[0010] The existing network control resources, for any given node,
can be either a control plane resource or a non control plane
resource. An example of a non control plane resource is network
management software (e.g., an OSS (Operation Support System)),
which forms part of the Management Plane.
[0011] It should be noted that this does not need to be done for a
complete end-to-end connection, but rather can be executed for the
portion of the end-to-end connection which is to be controlled by
the control plane. In other words, although a subset of the whole
network connection may undergo a transfer of control ownership, the
data being passed over the whole network connection is not
adversely affected.
[0012] According to one aspect of the invention, the method works
by permitting creation of new control plane connection(s) on top of
existing control and/or non-control plane connection(s) for a data
plane connection. Once the new control plane connection(s) is(are)
created then the old control and non-control plane connection(s)
is(are) terminated leaving only the new control plane
connection(s). Similarly, new control plane calls is(are) created
that is(are) associated with the new control plane connection(s),
and replace(s) the old control plane call(s) when the new control
plane connection(s) become(s) active.
[0013] In a further aspect, the present invention provides a method
for changing the extent of data plane resources controlled by a
control plane for a network connection which spans a contiguous set
of nodes, said network connection controlled by existing network
control resources, said method comprising the steps of: i) Creating
a new set of control plane resources for said network connection
such that said data plane resources are shared with said existing
network control resources; and ii) then terminating the existing
network control resources such that said data plane resources are
fully transferred to the new set of control plane resources without
disrupting said network connection. Such a method has particular
benefits when at least some of said existing network control
resources comprise existing control plane resources, or when the
number of nodes controlled by said new set of control plane
resources differs from the number of nodes controlled by said
existing control plane resources. According to one embodiment, such
a method includes creating connection control states for the new
set of control plane resources on every node; and mapping the
existing data plane resources to each new connection control
state.
[0014] Such a method can be used for growing, shrinking, splitting,
merging, or modifying the span of control of the control plane for
a network connection. In the shrinking case, it should be noted
that data plane resources no longer controlled by control plane
resources are transferred to non control plane resources.
[0015] A further aspect of the invention provides a method of
controlling a network connection between X nodes in a network,
wherein a first subset Y of said nodes is controlled by a control
plane, and a second subset (X-Y) is not controlled by a control
plane, comprising adjusting Y by a delta Z without adjusting the
data plane connections between said X nodes. According to one
embodiment, said adjusting Y step comprises: a) establishing new
control plane connections for Y+Z in parallel to the existing
control plane connections for Y, said new control plane connections
and said existing control plane connections sharing the same data
plane resources; and b) then terminating the existing control plane
connections such that said data plane resources are fully
transferred to the new control plane connections without disrupting
said network connection.
[0016] Further aspects of the present invention include a network
for implementing any of the above; a Network node for such a
network; and a computer program product embodied in a
machine-readable medium tangibly embodying computer executable
instructions for updating a network node to be compliant with any
of the above.
[0017] Other aspects and features of the present invention will
become apparent to those ordinarily skilled in the art upon review
of the following description of specific embodiments of the
invention in conjunction with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Embodiments of the present invention will now be described,
by way of example only, with reference to the attached Figures,
wherein:
[0019] FIG. 1 is a schematic network drawing, split into 2 parts,
Before and After, illustrating growing the span of control for the
control plane connection associated with a data plane
connection.
[0020] FIG. 2 is a schematic network drawing, split into 2 parts,
Before and After, illustrating shrinking the span of control for
the control plane connection associated with a data plane
connection.
[0021] FIG. 3 is a schematic network drawing, split into 2 parts,
Before and After, illustrating an example of splitting the span of
control for the control plane connection associated with a data
plane connection.
[0022] FIG. 4 is a schematic network drawing, split into 2 parts,
Before and After, illustrating an example of the reverse of FIG. 3,
namely, merging the span of control for the control plane
connection associated with a data plane connection.
[0023] FIG. 5 is a schematic network drawing, split into 2 parts,
Before and After, illustrating an example of reversing Head and
Tail end functionality for a control plane connection associated
with a data plane connection.
[0024] FIG. 6 is a schematic network drawing, split into 2 parts,
Before and After, illustrating an example of turning an SC
connection into an SPC connection.
[0025] FIG. 7 is a schematic network drawing, split into 3 parts,
Before, After Step 1 and After Step 2, illustrating an example of a
two step process for growing the span of control plane connection
for a particular data plane connection, according to an embodiment
of the invention.
[0026] FIG. 8 illustrates the two step process for merging two
control plane connections of a single data plane connection into a
single control plane connection, according to an embodiment of the
invention.
[0027] FIG. 9 shows the network objects for the example of FIG. 7,
according to an embodiment of the invention present in the network
before the expansion of the control plane's span of control.
[0028] FIG. 10 shows an example of the message sequence used to
create a new control plane call and connection objects in
accordance with the first step of the process.
[0029] FIG. 11 shows the objects after performing the first
step.
[0030] FIG. 12 shows the message sequence to terminate the original
control plane connection (and call) in accordance with the second
step.
[0031] FIG. 13 shows the objects after performing this
termination.
DETAILED DESCRIPTION
[0032] Exemplary embodiments of the invention will be described
with reference to the example of an ASON control plane, as
described in the Recommendation G.8080/Y.1304, Architecture for the
Automatically Switched Optical Network (ASON), which is a published
ITU-T Document, which is hereby incorporated by reference in its
entirety. However, it should be noted that the invention is also
applicable to control planes for other protocols and networks,
including ATM, Telephony, Frame Relay, ISDN, MPLS, GMPLS and X.25.
Note that ASON and ASTN are used interchangeably in this
specification. The term "connection" as used includes the
definition found in ITU-T Recommendation G.805 (2000), "Generic
functional architecture of transport networks" and also used in
ITU-T Recommendation G.8110/Y.1370 (2005), "MPLS layer network
architecture", both of which are hereby incorporated by
reference.
[0033] Furthermore, we discuss embodiments of the invention with
reference to modifying the span of control of connections. However
it should be noted that the invention is more broadly applicable to
communication services, which include calls and the connections
involved therein. It should be noted that the term "call" has a
technical definition, which is broader than the conventional
"telephone call" between two people. In this specification, a call
is the representation of the service offered to the user of a
network layer, while the connection is one of the means by which
networks deliver said service. There may be other entities used in
supporting calls, such as service specific processes. Without
limiting the generality of the foregoing, a call can be described
as an association between two or more users and one or more domains
that supports an instance of a service through one or more domains.
Within domains, the association is supported by network entities
that contain call state. Between a user and a network call control
entity and between network call control entities, there are call
segments. The call consists of a set of concatenated call segments.
More information about calls, connections and the control plane is
described in the Recommendation G.8080/Y.1304.
[0034] FIG. 1 is a schematic network drawing split into 2 parts,
Before and After, illustrating an example of growing the span of
control for the control plane connection associated with a data
plane connection. Such an operation may be required as control
plane domain grows to encompass nodes and links utilized by a data
plane connection but previously not under the control plane's
control. For example, ASON domain control plane growth to
incorporate a node previously managed by a non-control plane
network control resource, for example, network management software
(e.g., an OSS (Operation Support System)), which forms part of the
Management Plane.
[0035] As shown in the Before part of the figure, there are 6 nodes
10, 20, 30, 40, 50 and 60 involved in a connection each node being
controlled by existing network control resources. As shown, there
is an end-to-end data plane connection spanning each of nodes
10-60. In this example, a first subset of the nodes, namely nodes
20, 30 and 40 are part of an ASON domain 100. Accordingly, a
control plane connection 80 controls the connection between nodes
20 and 30 and between nodes 30 and 40. A second subset of the nodes
which are also involved in the call, namely nodes 10, 50 and 60,
fall outside of the ASON domain 100. Thus nodes 10, 50 and 60 are
controlled by non-control plane management software--e.g. OSS.
[0036] The AFTER part of the figure shows ASON domain 100 is
expanded to include node 50, and this expanded domain is shown as
ASON domain 150. Accordingly the control plane connection 180 now
spans nodes 20, 30, 40 and 50, i.e. the span of control plane
connection has lengthened/grown to encompass node 50. The call
associated with connection 80 is also modified to be associated
with the new connection 180.
[0037] FIG. 2 is a schematic network drawing, split into 2 parts,
Before and After, illustrating an example of shrinking the span of
control for the control plane connection associated with a data
plane connection. Such operations may be required as control plane
domain shrinks relinquishing control of one or more nodes utilized
by the data plane connection. For example, ASON domain shrinkage
releasing control of a nodes to an OSS. In this example, FIG. 2
effectively represents the reverse operation of FIG. 1. In the
Before half of FIG. 2, node 50 is part of the ASON domain. In the
After half of FIG. 2, node 50 is no longer part of the ASON domain,
and it is subsequently controlled by an OSS.
[0038] FIG. 3 is a schematic network drawing, split into 2 parts,
Before and After, illustrating an example of splitting the span of
control for the control plane connection associated with a data
plane connection. In this example, a single domain is divided into
2 smaller domains. Such operations may be required as a control
plane domain is divided into 2 (sub) domains, for example,
resulting from a divestiture or re-organization.
[0039] FIG. 4 is a schematic network drawing, split into 2 parts,
Before and After, illustrating an example of the reverse of FIG. 3,
namely, merging the span of control for the control plane
connection associated with a data plane connection. In this
example, 2 smaller domains are merged into a single ASON domain.
Such operations may be required, for example, resulting from a
merger, acquisition or re-organization.
[0040] Other examples of changing the span of control for such
connections by reversing the Head and Tail end functionality of the
connection, which is illustrated in FIG. 5, or by turning a
Switched Connection (SC) connection that is initiated by a user,
into a Soft Permanent Connection (SPC) connection that is initiated
by a management plane application. Turning an SC connection into an
SPC connection is illustrated in FIG. 6. This involves removing the
use of a UNI between a client and network.
[0041] It should be appreciated that these all represent simplified
examples, and other modifications can be made; for example, more
than one node can be added or removed, or multiple domains can be
involved with splits or mergers.
[0042] Each of these adjustments to the span of control can be
implemented by a two-step process according to an embodiment of the
invention:
[0043] 1. New control plane connections are created in addition to
at least some of the existing network control resources of a data
plane connection. Where their data plane resources are common,
resource sharing is applied.
[0044] 2. Once the new control plane connections are created then
the network control resources to which resource sharing is applied
in the first step, are terminated. Note that as part of this
termination the ownership of the affected segments of the data
plane connection are transferred from the existing network control
resources to the new network control resources. Control plane calls
associated with the replaced control plane connections are also
replaced with calls associated with the new control plane
connections.
[0045] It should be noted that although described in the plural,
any of the connections can be singular.
[0046] Note that the new and old control plane connection(s) share
the same data plane connection resources. The resource sharing can,
for example, be implemented utilizing the resource sharing
mechanisms described in U.S. Pat. No. 5,848,055, and in patent
application Ser. No. 10/717,648, filed 21-11-2003 with the US
Patent Office, both of which are hereby incorporated by reference.
The resource sharing mechanism allows two independent control plane
connections to share the same data plane resources. In the example
of ASON, these resources include SON ET/SDH time-slots. Note also
that this mechanism can be implemented in-service as it doesn't
impact the data plane connection, but simply manipulates control
plane connection(s) associated with the data plane connection.
[0047] An example of the above two step process for growing the
span of control plane connection for a particular data plane
connection, is illustrated in FIG. 7, according to an embodiment of
the invention. The BEFORE network contains a single data plane
connection, 200, with an associated control plane connection, 80,
in the ASON Domain. In this example, the ASON Domain is to be
extended to include another node (node E), thereby requiring
modification to the control plane connection, i.e. to extend the
span of control of the control plane connection. The first step is
to create a new control plane connection, 180, such than the
existing control plane connection 80 and the new control plane
connection 180 share the same data plane connection 200. A new call
associated with connection 180 is also created. Note that at this
point the ownership of the data plane connection 200 within the
extended ASON Domain remains with the original control plane
connection 80. The AFTER STEP 1 network shows this scenario. Once
the new control plane connection 180 is successfully created then
the second step is to terminate the original control plane
connection 80 and its associated call. During this termination, the
ownership of the data plane connection 200 is transferred from the
original control plane connection 80 to the new control plane
connection 180 and its associated call. The AFTER STEP 2 network
shows this scenario.
[0048] More details regarding the example of FIG. 7 are discussed
below with reference to FIGS. 9-13.
[0049] FIG. 8 illustrates the two step process for merging two
control plane connections (and calls) of a single data plane
connection into a single control plane connection, according to an
embodiment of the invention. The BEFORE network contains a single
data plane connection 800, a first associated control plane
connection 820 for ASTN domain A and, a second associated control
plane connection 840 for ASTN domain B. The two ASTN Domains are to
be merged to form a single ASTN Domain, thereby requiring
modification to the two control plane connections, i.e. to merge
them into a single control plane connection. The first step is to
create a new control plane connection, 860, such that the two
existing control plane connections 820, 840 and the new control
plane connection 860 share common data plane resources from data
plane connection 800. A call associated with connection 860 is also
created. Note that the ownership of the data plane connection
within the newly merged ASTN Domain remains with the two original
control plane connections 820 and 840. The AFTER STEP 1 network
shows this scenario. Once the new control plane connection 860 is
successfully created then the second step is to terminate the two
original control plane connections 820 and 840, and their
associated calls. During this termination, the ownership of the
data plane connection 800 portions is transferred from the original
control plane connections 820 and 840 to the new control plane
connection 860 and its call. The AFTER STEP 2 network shows this
scenario.
[0050] FIGS. 7 and 8 illustrate two examples. However the invention
is applicable to other adjustments to the span of control of the
control plane connection, including the examples discussed above
with reference to FIGS. 2, 3, 5 and 6. Note the invention is
applicable to calls and the connections which comprise the
calls.
[0051] FIGS. 9-13 show details of the network objects for the
example of FIG. 7, according to an embodiment of the invention,
utilizing a distributed control plane implementation. FIG. 9 shows
the objects present in the network before the expansion of the
control plane's span of control. FIG. 9 shows that each of the
nodes B, C, and D have both a call state and connection state in
the control plane. The hashed objects represent the data plane
connection objects, while the dotted objects represent the existing
control plane call and connection objects. These control plane call
and connection objects reside only within the boundaries of the
ASTN domain which is to be expanded to also include node E.
[0052] FIG. 10 shows an example of the message sequence used to
create a new control plane call and connection objects in
accordance with the first step of the invention. This new control
plane call and connection objects are created by establishing
connection objects between each successive node from node B to node
E, and call objects on nodes B and E. Note that each node is shown
to have hardware for providing the physical connections, and a Link
Resource Manager which controls the data plane hardware used in
data transfer. Note that for a brand new call, the Link Resource
Manager would control the setting up of a physical connection
(i.e., the data plane resources, e.g. controlling the hardware
ports, fabric, channel etc) for a data plane connection. However
during step 1, as the data plane resources are already established,
the Link Resource Manager does not establish additional data plane
resources, but rather associates the existing data plane resources
to the newly established control plane connection. As previously
stated this is done so that the data plane resources are shared by
the existing control plane connection 80 and by the new control
plane connection 180.
[0053] FIG. 11 shows the objects after performing the first step,
which include the data plane connection objects, the original
control plane connection (and call) objects, and the new control
plane connection (and call) objects. Note that the original and the
new control plane connection XCON objects representing the data
plane connection within Link Resource Mgr share the same data plane
connection XCON objects. At this stage the ownership of these data
plane connection XCON objects remains with the original control
plane connection XCON objects.
[0054] As stated, this example illustrates a distributed control
plane implementation where each node includes the controller for
executing a Link Resource Manager function, and Connection Control
Function and a Call Control function (the Ovals), where each
function creates an instance for each connection (the squares)
and/or call.
[0055] FIG. 12 shows the message sequence to terminate the original
control plane connection (and call) in accordance with the second
step, while FIG. 13 shows the objects after performing this
termination. Note that during this termination the ownership of the
data plane connection XCON objects (hashed) has been transferred
from the original control plane connection XCON objects to the new
control plane connection XCON objects.
[0056] Note that a centralized control plane implementation is also
possible, and within the scope of the invention. Also, although we
have stated that existing data plane resources are not disrupted,
an embodiment of the invention can allow for changes to the data
plane resources--for example by adding bandwidth to an existing
call--see below. What is important is user services are not
disrupted. As another example, a call containing a Exterior
Network-Network Interface (ENNI) can be replaced by a call that
does not contain that Exterior Network-Network Interface. Similarly
a call can be replaced by a call that includes Exterior
Network-Network Interface. Thus aspects of the invention may be
useful even if the nodes involved do not change.
[0057] As stated, an embodiment of the invention can allow for
changes to the data plane resources--for example by modifying the
bandwidth of an existing call. We will discuss an example of how to
do this in terms of the RSVP-TE signalling protocol.
[0058] An initial call is established when the first connection is
established. The UNI-C sends a PATH message to the UNI-N to request
call and connection creation. The PATH request contains a
SESSION_ATTRIBUTE TLV with SE Style requested flag set. The request
does not contain a valid call identifier. The call identifier is
assigned by the source UNI-N and used in all subsequent messages at
the source and destination UNI-C. If the source UNI-C subsequently
wants to modify the call by modifying the connection bandwidth, it
will generate a new PATH message with the same Call ID it received
in the RESV for the first connection. The Call ID is used to
correlate the various connections at the UNI-C and UNI-N. This new
PATH message will have a different LSP_ID and MESSAGE_ID but the
same TUNNEL_ID. A new RESV message is generated in the reverse
direction. There is a single RESV state that corresponds to all
PATH states that share the same bandwidth, i.e. have the same
TUNNEL_ID. There is a single RESV message sent, but its contents
will change when connections are added or removed. The RESV message
includes the bandwidth of the largest bandwidth request it received
in the PATH messages and the SE flow descriptor includes the
FILTER_SPEC of all corresponding PATH messages. If the RESV message
includes a RESV_CONF object, a new RESV_CONF message should be sent
by the source UNI-C which includes the new SE flow descriptor. At
this point, the data can be transmitted end to end with the new
bandwidth parameters, but connection state exists in the original
and new PATH messages. The original PATH message can now be deleted
and a PATH_TEAR generated by the UNI-C will release the RSVP states
at each node. The deletion of the PATH state will result in a
change in the RESV message SE flow descriptor contents as it will
contain one less FILTER_SPEC. This corresponds to the step that
terminates the original control plane connection state.
[0059] A bandwidth decrease can be achieved with an identical
message flow although the RESV_CONF may not be necessary in that
case. The new bandwidth would become effective at the PATH_TEAR
stage as opposed to the RESV_CONF stage.
[0060] Additional information relating to the above modifications
of the bandwidth of existing calls can be found in Call
Modification RSVP Details for UNI 2.0, Contribution Number:
2005.216.00, Optical Internetworking Forum (OIF), 2005-06-30, which
is hereby incorporated by reference in its entirety.
[0061] In the prior description, for purposes of explanation,
numerous details have been set forth in order to provide a thorough
understanding of the present invention. However, it will be
apparent to one skilled in the art that these specific details are
not required in order to practice the present invention. For
example, specific details are not provided as to whether the
embodiments of the invention described herein are implemented as a
software routine, hardware circuit, firmware, or a combination
thereof, or whether the control plane is centralized or
distributed. Furthermore, those of ordinary skill will recognize
that the features of the functionalities described herein can be
implemented using processing hardware and software, such as
computers or microprocessors and corresponding program and data
memories. Such processors can be individual local processors or can
be implemented in a central processor. Distributed processing
techniques may also be used. Additionally, individual functions can
be built in hard wired logic as may be desirable for the system
implementation. Thus, the system according to the invention is not
limited by the form of computer or processor construction, but can
be implemented using any processing technique now known or later
developed. For example, those of ordinary skill will recognize that
a Link Resource Manager according to the invention can be
implemented in a single processor or single unit or can be
implemented in a plurality of units performing portions of the
overall Link Resource Manager functions.
[0062] Embodiments of the invention may be represented as a
software product stored on a machine-readable medium (also referred
to as a computer-readable medium, a processor-readable medium, or a
computer usable medium having a computer readable program code
embodied therein). The machine-readable medium may be any type of
magnetic, optical, or electrical storage medium including a
diskette, compact disk read only memory (CD-ROM), memory device
(volatile or non-volatile), or similar storage mechanism. The
machine-readable medium may contain various sets of instructions,
code sequences, configuration information, or other data. Those of
ordinary skill in the art will appreciate that other instructions
and operations necessary to implement the described invention may
also be stored on the machine-readable medium. Software running
from the machine readable medium may interface with circuitry to
perform the described tasks.
[0063] Accordingly, one aspect of the invention provides a computer
program product embodied in a machine-readable medium tangibly
embodying computer executable instructions for controlling at least
a portion of a network of X nodes, wherein at least a subset Y of
said nodes is controlled by a first control plane connection, said
computer executable instructions comprising computer executable
instructions for establishing a second control plane connection
between a second subset Z of said nodes in such a manner that said
second control plane connection shares data plane resources with
said first control plane. According to one embodiment, the computer
executable instructions for establishing a second control plane
connection comprises: a) computer executable instructions for
establishing a second control plane connection in parallel with
said first control plane, such that both said first and second
control plane connections share at least some data plane resources;
and b) computer executable instructions for terminating the
existing first control plane connection such that said shared data
plane resources are fully transferred to the said second control
plane connection without disrupting said data plane resources.
According to some embodiments, Z does not equal Y. However in other
embodiments Z=Y, but the data plane resources of Z differ from the
data plane resources of Y (e.g., the bandwidth of Z has either
increases or decreased from Y). According to some embodiments, said
computer executable instructions can further comprise instructions
for: creating new connection control states for the second control
plane connection on each of said Z nodes; and mapping said shared
data plane resources to each new connection control state.
According to some embodiments, said computer executable
instructions can further comprise instructions for: creating new
call control states for the second control plane connection;
creating new connection control states for the second control plane
connection on each of said Z nodes; associating the new connection
control states with the new call states; and mapping said shared
data plane resources to each new connection control state.
[0064] The above-described embodiments of the present invention are
intended to be examples only. Alterations, modifications and
variations may be effected to the particular embodiments by those
of skill in the art without departing from the scope of the
invention, which is defined solely by the claims appended
hereto.
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